docs: def cli(env, volume_id, new_size, new_iops, new_tier):
      """Modify an existing file storage volume."""
      file_manager = SoftLayer.FileStorageManager(env.client)
  
      if new_tier is not None:
          new_tier = float(new_tier)
  
      try:
          order = file_manager.order_modified_volume(
              volume_id,
              new_size=new_size,
              new_iops=new_iops,
              new_tier_level=new_tier,
          )
      except ValueError as ex:
          raise exceptions.ArgumentError(str(ex))
  
      if 'placedOrder' in order.keys():
          click.echo("Order #{0} placed successfully!".format(order['placedOrder']['id']))
          for item in order['placedOrder']['items']:
              click.echo(" > %s" % item['description'])
      else:
          click.echo("Order could not be placed! Please verify your options and try again.")